Just because they are expensive doesent mean they are good. Siemens Deka can be bought pretty cheaply and are far better.
Ok, so anyone got part numbers for the correct fit Siemens for 440cc and 550cc to fit? I might do a bit of R&D to see if they make more power, if they do work better then you should need less fuel and still make the same if not more power?
They are quoted as 630cc too big, also really want a UK seller.
think they do then in other sizes too.
quick google
http://www.injectorsonline.com/indivprod.php?cid=74&scid=11
then google in the UK when you have the part number
better list of part numbers here
http://www.fiveomotorsport.com/import-high-performance-fuel-injectors/
denso 440
semens 550
http://www.fiveomotorsport.com/import-high-performance-fuel-injectors/?itemid=335
again you would have to find a UK seller and then pay twice the price
Odd these siemens ones are 630cc
“This Siemens 625-635cc injector set has been custom fitted for all Toyota 1ZZ and 2ZZ Engines, Mitsu Evo, etc”
Still no 550cc to buy, I’ll get some ready if my 440cc can’t cope and see how well they perform 
Adrian, what could be the drawback of the 630cc???
Fran�ois
overfueling on idle and low revs, the larger the injectors the harder it is to control low throttle applications as the pulse width on the injectors is so short.